Chucking mechanism for a tapping machine



g- 19, 1952 J. H. WILLIAMS 7 2,07,054

CHUCKING MECHANISM FOR A TAPPING MACHINE Filed Dec. 2811949 4 Sheets-Sheet 1 Fig.-|

o e: f @Q 0 e a I a i vJames Howard Williams INVENTOR.

WW ATTORNEY Aug. 19, 1952 .1. H; WILLIAMS 2,607,054

CHUCKING MECHANISM FOR A TAPPING MACHINE Filed Dec. 28, 1949 4 Sheets-Sheet 2 Fi'q. 2

l Inn m1 INN James Howard Williams INVENTOR.

ATTORNEY g- 19, 1952 J. H. WILLIAMS 2,607,054

CHUCKING MECHANISM FOR A TAPPING MACHINE Filed Dec. 28, 1949 4 Sheets-Sheet 5 Fig. 3.

' James Howard Williams INVENTOR.

ATTORNEY Aug. 19, 1952 J. H. WILLIAMS Filed Dec. 28, 1949 4 Sheets-Sheet 4 Fig. 4 6 0 E- 6'0 m M I] i: E a) 46 i 76 72 y 78 1 76 0 E6 54 68 60 In llll ATTORNEY nisrn:

Patented Aug. 19, 1952 1 James .HowarcLsWilliams, LincQhjsAKL-L 97545 52319 1 to, Grimell damnat litey lqeme I031: srmret qepfilJeiawa e An l catiq nmm rzfi Ss 1 W 1 53 ;5;Claimse.-M:(Cllore-4 97.):

This--inventionrelates toimprovements in whatever features. 01- ipatentable noveltylexistim chucking -meehanism for a tappjfig mahine the invention disclosed W 1" More especiallyit-has to dp-with irnpgq ea I nthe'accompanyingidrawingsz V pe t i a -p pe fittingjt be manually; Fig, 1-' a f-ront-elevation of a tappingimaeliine:

placed inthe chuckinmechanism land ang de r- 5 embed-31mg my inrpmvdschuckingemechanismgm, ate holding pressure applied and thereagt ap Fig. 2 is a-side elevation ofwtheisanieyasiseen" p yingfpower-pressure to accurately p ositiqn the frOmthe Ief-tinFigiI; V V. v fitt ng-and hold itfilfmlyin place-while th Fig. 3 is a similamelevationipartlyiiinwsecticn, threads'are cut; I as on line 3- 3-;of-Fig-.-1-;'

Chuckingmechanisms heretofore used have F'igt leis-a plah-vieWinseetion asionsline;41-4 been objectionablepbecause of theuloss of time of -Fig-; 2 '--a'r;idi .t required tc maintain them in operating cbnQitip Figs; -5 ands are elevation's partlyiin sectibn;.. This has been due in large part to -the presence sh Wing' -'detai -1S ofthe -chuckirig mechanism in. of-numerous flat surfaces between the relatively difieiflerit-relat-i vepositibns J Yine Dartson which surfaces, the trimm ipgs; Rejerring moreyparticularly tottheidrawin'gsi. Q pS lTQm. the W9 1i. being out. pqulcl fallangi thetappingmaehir e shown for piirposesbfJill'us. become; entrapped between the mating mqv in'g, tratip'nhas-a base {11'onwhieharemo'unt'ed three u aces; *T iS WOuId cause rapid and serious tapping units [2; l4-and46witl =thein respective ea and. require frequent repairs to the meglga;, taps 118,- ;;ai1 d 2-2;; arrar ged with=twoof -them.;

' 20 in hprizeptalalignmerit and the thirdbne vertie t s, .,pr nc p l obje t ofihthe present invention cally disposed with its axis passing thmughithe. t 1119111113 certain oft the p arts qf my imprqyed common horizontalams-df tlie cther two.:.; This ephamsmo asin e shaft which ext nds j ori-r is helisuai-ar ns'em m -x ti tools for QRWHSL' nuthe tapping machin'euand, a portipn. tappiI g a pipe T-butit istQb -und'erstodd that: ofwhich underlies thenpoint of intersection b f my ir nprp ved 'chgckingq -neclianism -can -be em the axis of thecutting tools TheADrQYiS QnHOfj plpyedwith'tapin'g machines; havi ng rit bmablexiriv is in sh ft, as, tlqe i ideway oniwhighjhe aqj t bl t ijiiigs -uriits---;wh ich can be set at.- moving partsslide presents l q-surfaces pn whicn angles td 9151a aricther tOCl-1 t"-45- '1bOWS e1' fittines trimmings; wi ll engrmally remain. Such as mayr with their 'hples-farran'ged --at-unus1ial-angles=toqment rily'ibala ce 0.1 ,the sulfia'ce QfQbh e sh ft] each ether. Likewisejmy inventiengcan 'be'used are rea l is odg d andfall bGIqW thesham '1 with flttipgs arid cutting means-f r mitting both fore t y an W0 h@mse ve ineb tween the i tern l and wen th fi fiifing#- aftan hewpartsiwh hrslide upqn it-qr thet, ShQlj t by prqyiding jaws bf-{suitable cenfigtlr rin s t hrgu hu. iwh c a 'e h it-. it s id s. tio to receive f ari;d properly "grip-a fitting my .i iafurther biect or the re en mention i. 1 m: ds chuqk l. m ii ad pr r de aip r 0f vjaw" members; wh he z i e d neelmb t-fili .ni ef i fi h a an l y position d. a ai s 'Ja...fitt n ridJpliil ica.v hreaded ld-by sprin mea s vexertingiamcder te pres-U Lhjave nqtsc 'sq q slia be s' h it bsure on the fitting. It is a still'further bj t'to, ping ;mac l 1ir e,apartfirqrn my imfireiiementgbtit prov d P essure actuate meaesiq here?! r it is; to. e nde -@0091 hat 'l 'im {Refine are? ovi the sh ftiandwithwitthe Jawmemher's, .H resent' in the machineiferfirotati" {the rage in dpositi'quthefl t n p q e .aepmentwith; laqth v direc ion Q -4tot nah 0r e 6 m hei tt ne tQQ s an i o imamtaini heiflttingin them tqwardandirqm afittifito bethjreaddsaid pgsition' while ,jthe tapping'eccursj Uppn The present inyezi en h *tridg'fWithithe ithdrawal of ther pqlsi omi thelnowit l eaded chucking, meg. .W'hQ TQ S i -th m meie fi ti h pres ure c ua ed means.r iu ns the; i1 't q ihe dut j w embers to a. p sition-wh re the moderate ho'ldin xpressu eg an befi anua ly eleas fl. lt ie thread drfi tinguremqve vfrbmv h jawwm mb rs, andianvunthreadedvpiece o'fiworiz ins d-i,

Thelbe'stimocle in which I ha vcqntemn e applying ,the principles of ,my imprpyements is 2 disclosed in.., the accompanying 'clraWi r' gs }of1it v I a I I e i A efi b s-d d. rim r i l st r b to receive a fitting. Fig. 6 shows he posltion f f cause; it is intended thatltl e rpatent shal'l .-c oyer the chuckling" mechanism after, the z fittir g lias byt=suitabletexpression ix the, appended clai'msl i beeryplaced inutl e jaw rriempersan t actuation of the mechanism has been completed.

Looking now at Fig. 3, a cylinder 24 is mounted at the rear of the machine and the ends thereof are connected by pipes 28 and 28 with a treadle controlled valve 36 to which air under pressure is supplied through a pipe 32 (see Fig. 1) and from which air can be released to at mosphere via a pipe 34. Within the cylinder 24 is a piston 36 from which a pison rod or shaft 38 extends horizontally forward beyond the tapping units and under the intersection of the axes of the cutting tools. Keyed to this shaft near its forward end are a pair of jaw members 46 and 42. These members are separately mounted on the shaft and can separately slide longitudinally therealong but can not rotate with respect to the shaft itself. The latter is of course movable along its longitudinal axis and may be rotated slightly about this axis because of limited free play between a key M -which is carried by the shaft and loosely engages a one end of this cylinder are vent holes 56a, and

at the other end are holes to receive pipes 54 and 56. The pipe 54 is connected through a check valve 58 to a strainer 66 and the other pipe 56 is connected through another check valve 62 to a distributing nozzle 64 at its upper end. When the shaft is moved forward, or to the right as seen in Fig. 3, lubricating oil is drawn from the bottom of casing 48 through the strainer 66 past the open check valve 68 and into the cylinder 56. During thisstroke of the piston the check valve 62 is closed. When the piston 52 moves through its other stroke, from right to left, the check valve 58 is closed and the oil is forced upward through the .pipe 56, past the now open check valve 62 to the nozzle 64 whence it is sprayed over the gears and other parts (not shown) housed within the casing 48.

The shaft 38, between the jaw members 42) and 42, has a threaded portion on which are screwed a pair of nuts 66. When these nuts are adjusted in position and tightened against one another they serve as a stop member against which the jaw member 46 can make contact. Beyond the forward jaw member 42 substantially at the end of shaft 38 is a-hub 68. fixedly mounted thereon. The rearward face of this hub 68 seats against a shoulder '38?) on shaft 38, being clampedthereto by a nut 16 screwed onto the end of this shaft.

This hub 68 carries an upstanding arm 68a on which is pivotally mounted a sort of bell crank lever 12 one arm of which carries a handle 12a and the other arm 12b of which is pivotally connected to a bifurcated link 14. The latter is also pivotally connected to the forward jaw member 42. This link and the bell crank lever serve as a toggle joint between the'jaw member. 42 and hub 68. Connected to the hub 68 and to the rear jaw member 46 on both sides thereof, are. tension springs .16 which always tend-to move the rear jaw member toward the hub (Figs.

The rear face of the jaw member 40 is provided with a centering slot 46a and on the casing 48 is mounted a centering pin 78 having a camshaped end 18a of a size and shape to engage nicely the side walls of the slot 45a. This pin not only acts as a stop for the jaw members so that the axis of the holes in a fitting will be in the plane defined by the axes of the taps but the engagement of the cam-shaped end of the pin with the cam-shaped slot 60a can cause sufficient rotation of the jaw members to bring these several axes into perfect alignment.

The operation of the chucking mechanism is as follows. With the treadle actuated valve 36 so positioned that the air pressure is effective on the rearward face of the piston 36, the movable parts of thechucking mechanism will be in the positions shown in Fig. 5. The handle 12a is held in its forward position which means that the arm 12b and the link 14 are inclined upwardly and hence the forward jaw member 42 is in its most forward position against the hub 68. the stop nuts 66 being held in that position by the pull of the springs '56. The jaws to and 82 are accordingly in their wide open position ready to receive a fitting. I

A fitting F is manually placed in the space between the open jaws and the handle 72a is 1 then pushed rearward. This swings the arm 72b of the bell crank lever and the link 14 downward and causes the forward jaw 82 to push against the fitting and bring the latter against the rearward jaw 88. As the toggle joint continues to swing downward the rearward jaw 80 and the jaw member 46 are moved along the shaft 38 away from the stop nuts 66. This permissible relative movement of the jaws enables them to engage the work suitably despite such minor variations as may occur between one fitting and another. When the toggle joint reaches the end of its downward swing with the bell crank arm 12b and the link M both inclined below the horizontal, as seen in Fig. 6, the fitting is held in the jaws by the moderate pressure exerted by the springs '16. In this position the fitting is still forward of the cutting tools which must enter the holes in the fitting.

The position of the treadle valve 39 'is now changed to permit the air in the cylinder on the rearward side of the piston 36 to escape via the pipes 26 and 34, and the pressure supply from pipe 32 to pass through pipe 28 into cylinder 24 and become effective on the forward side of the piston 36. As the piston moves rearward, pulling the shaft 36 with it, the fitting is likewise moved rearward because the hub 68 and jaw members 46 and 42 move with the shaft, the force being transmitted from the hub 68 to the jaw member 42 and from the latter to the other jaw member 46 by the fitting F.

When the rearward jaw member 46 reaches the pin 18,.the engagement between the canishaped end l 8a of the'later and the walls of the centering slot 4641 causes the jaw-members, the jaws and the shaft 38 to rotate if the hole or holes in the fitting are not in alignment with the taps. This slight rotation of the movable parts lines up the fitting so that its holes are accurately positioned with respect to the taps when the pin 18 stops further rearward movement. of the jaw members; The fitting is thus held very firmly in its proper position while the tapping operation is performed because the full effect of the pressure on the piston 36 is transmitted by the shaft 38, the nut 16, the hub 68, the bell crank ber 42, while the rearward jaw member 40 is The rearward jaw member 46 is against amass and the tapswithdrawn; -the position of the.

treadle, valve 30. is again shifted so thatcpressure is applied to'the rearward face of pistoir' 36; .This causes the shaft 38 to move forward'and'of'course removes the-heavy holdingcpres'surelon the fitting. ,Ijhe latter is not released, however, because;

the pull ofgthe springs 16 is still effective-to hold thesjaw iillagainst the fitting J I-o release t-he fitting the operator swings thehandle 12a forward to shift the jaw member 42 against the hub 68 while the rear jaw member, still under the pull of the springs 16, brings up against the stop nuts 66. The jaws thereupon separate allowing the fitting to drop through a hole 84 in the top of the base In and slide down a chute 86 to a box or basket outside the machine. The parts of the chucking mechanism are again in the relative positions shown in Fig. 5, ready to receive another uncut fitting.

Looking at Fig. 4 especially, it is obvious that substantially all of the shaft 38 outside of its bearing 46 is covered by the jaw members, the toggle joint (12-14) and the hub 68. Consequently very little of the trimmings from the fitting can fall directly on the shaft, and such as do reach the shaft are met with a surface from which they normally slide off and pass downward through the hole 84. Accordingly practically none of the trimmings can work their way between the shaft and the other elements which are slidable with respect thereto. This results inno undue wear and materially reduces the time lost in the shut-down of the machine heretofore experienced where the trimmings can work in between relatively moving parts and cause excessive wear.

The initial moderate pressure imposed on the fitting by the springs 16 allows the fitting to adjust itself to the configuration of the jaws so that when the latter are finally positioned by the engagement of the centering pin l8 and the centering slot 40a the fitting will be accurately placed with respect to the cutting tools.

I claim:

1. Chucking mechanism for a tapping machine comprising a movable shaft; pressure actuated means for moving said shaft forwardly or rearwardly with respect to the cutting tools of said machine; a forward and a rearward jaw member mounted on said shaft for movement therealong; work engaging jaws carried by said jaw members; means for moving said jaw members with respect to one another for engaging a piece of work between them; means on said shaft for engaging said forward jaw member to effect movement of both said jaw members and the work piece rearward with said shaft; an adjustable centering stop mounted on the frame of said machine; and a centering slot in the rearward jaw member adapted to engage said stop and by the last said engagement effect the accurate positioning of said work piece with respect to the cutting tools.

2. Chucking mechanism for a tapping machine comprising a movable shaft; pressure actuated means for moving said shaft rearwardly and forwardly with respect to the cutting tools of said machine; a forward and a rearward jaw member mounted on said shaft and movable therealong; a hub member secured to said shaft forwardly of said forward jaw member; means interposed betw ene ai 111b, m b t nds-said f swatdei t member, for, moving said forwardjaw em along-tilesaidshaft toward,one side ofithe '7 pri g:me r a o ol inei bee sarw r ria 111 r-a e n i ee h id s d-=wq ki ansi. centering; means mounted on theframe of. the

machineander gageablev by the. rearwarduj member upon-,movement, of; the. shaft a J w membersirearwardly by; the .said, ressur ,act

With-n wes er ileims to s-1 comprising a pressure actuated shaft extending below the intersection of th axes of the cutting tools of said machine; a forward jaw member and a rearward jaw member individually slidably mounted on said shaft for holding the work to be tapped; manually actuated means providing an unyielding connection between the forward jaw member and said shaft; spring means urging the rearward jaw member toward the forward jaw member for lightly holding the work between said jaw members before said work is positioned with respect to said cutting tools; and travel limiting means mounted on the frame of the machine and engageable by the rearward jaw member for limiting the rearward travel of said rearward jaw member so that the force exerted rearwardly by the pressur actuated shaft urges the forward jaw member toward the rearward jaw member and thereby holds the work therebetween firmly during the tapping operation.

4. Chucking mechanism for a tapping machine comprising a movable shaft located with its axis below the point of intersection of the axes of the cutting tools of said machine forward and rearward jaw members keyed to said shaft and slidable therealong; each having a jaw suitably shaped to clamp a fitting between them; a hub member secured to the shaft; spring means connecting said hub member with and tending to urge said rearward jaw member forwardly toward said forward jaw member; a stop on said shaft intermediate said jaw members for limiting the forward travel of said rearward jaw member along said shaft; a manually actuated toggle joint interposed between said hub member and said forward member for moving said forward jaw member along said shaft toward said rearward jaw member to engage a fitting between them and move said rearward jaw member away from said stop so that the fitting is held between the jaw member under the force exerted by said spring means; [pressure actuated means for moving said shaft and jaw members rearward; an adjustable stop having a cam-shaped end mounted on the frame of the machine in the line of travel of the rearward jaw member; and a cam-shaped slot on said rearward jaw member adapted to engage said cam-shaped stop and by said engagement insure the proper positioning of the fitting with respect to the cutting tools; the said fitting being held firmly in place during the cutting operation.

5. Chucking mechanism for a tapping machine comprising a movable shaft located with its longitudinal axis below the intersection of the axes of the cutting tools of said machine; a pair of jaw members slidably but non-rotatably mounted on said shaft each having a jaw suitably shaped to engage a fitting between them; a hub member fixed on said shaft; a toggle joint interposed between said hub member and one of the jaw members for moving the last said jaw member toward acting to impose a moderate pressure onthe flttmg by the jaws; meansfor applying force'to 4 said shaft to move it along its said longitudinal axis; and a centering'stop momited o-n the fixed v 10 Number frame of the machine and; arrangedm be engaged by the said other jawmember and arrest the movement-of said shaft and other movable members with the fitting, ifi' pesi ti on to he eh gaged by the taps.

JAMES HOWARD WILLIAMS.

REFERENCES CITED The follbwing references are of record in the file of this patent: V

UNITED s'rATEs PATENTS Name 971,979 Evans Oct. 4:, 1910 $402,411 Kent June18, 1946' Date 

